Design and Fabrication of 5 GHz Miniaturized Bandpass Filter Using Superconducting Microstrip Quasi-Spiral Resonators

We propose a miniaturized novel microstrip quasi-spiral resonator (QSR) system composed of rewound-type spiral resonator and c-type spiral resonator. We have also designed a 5 GHz superconducting 4-pole bandpass filter (BPF) using QSR for international mobile telecommunication (IMT)-advanced base station receiver applications. The filter has been fabricated using a single-sided MgB2superconducting thin film deposited by thermal co-evaporation technique. The measured performance of the BPF has been found to show close agreement with the simulated one.